Trigger type collapsing tap



' 5 w. J. HOGG TRIGGER TYPE COLLAPSING TAPS Filed Aug. 20,1945

4 2 Sheets-Sheet l 7, 1945- w. J. HOGG TRIGGER .TYPE COLLAPSING TAPS I 2 Sheets-Sheet 2' Patented Aug. 7, 1945 TRIGGER TYPE COLLAPSING TAP William J. Hogg, Cleveland, Ohio, assignor to The National Acme Company, Cleveland, Ohio, a

corporation of Ohio Application August'20, 1943,-Serial No. 499,331 I reclaims. This invention relates to threading tools such as taps and dies and, more particularly, to the means for insuringnthe positive collapsing of the chasersuponcompletion of the thread cutting 9 operation, the? principal object of the invention being to provide such a device that will be positive in operation; simple in construction and inexpensive to manufacture. I the drawings accompanyingand forming a part ofthis specification;

Fig. I; is a;tran sversevvertical section of .a tap with the invention applied thereto. 7 21-is a section at right angles to Fig; 1. Fig. 3 i-sa vertical section taken on line 33 of Figmln t t Fig; 4 is a front elevation of the tap shown in Fig.1. I

t Fig. 5-isa transverse'vertical sectiontaken on line 55 of FigqZ- I I Fig. 6 is a transverse vertical section taken throughlthe tap and showing the operating cam and its appurtenances a t .Fig. 7 is a detailviewofthe cam and its asso-' ciated. collar.-

Sis a vertical section of the cam nested. with thercollan-and FigLSisapaI'tiaI plan detailof the body. M Similar characters of reference indicate correspondingtparts in the severalviews. g

Bei'or e explaining in detail the present improve ment andmode of operation thereof I desire tohave it understood thatlthe invention is not limitedito thedetails of construction andtarrange merit of parts illustrated in the accompanying drawings since the invention isv capable of other embodiments, and that the phraseology employed is for the purpose oi description andnot of limitatioln. H a 1 This improved tap comprises a body portion 2 having" atithe" rear thereof a shank 3 for attachmerit-to the holding means of a threading machine and, at the front thereof, radial slots 4 for therec'eption of chasers 5. l

Within an axial bore}; of the body '2 is located an axially shiftable core piece] having at the rear end the usual spring 8 for shifting the core piece at the proper time to retract the chasers and at the front" end suitably secured thereto a tapered nose piece 9. This nose piece is provided with tongues l0 and grooves l l' for engaging similar tonguesand grooves of the'chasers 5. .The chasers are held in the slots t of the body and in engagement with the nose piece 9 by means of a front plate 12. Thus, it willfbe observed that the axial shifting of the core piece Will'effect radial shifting of the chasers to collapse them out of the work at the proper time upon completion of thethread cutting operation.

Surrounding the body 2 is an axially shiftable collar or sleeve l3 carrying toward its front end a tie bar 14 hereinafter to be more fully described and toward its rear end is provided with a circumferential slot l5 for the reception of an arm].- ate trigger cam or latch it having its front edge beveled as at H. This cam I6 is urged outwardly by means of suitable springs I8.

Located'in therearof the collar I3 is an adjusting ring or collar is, having suitable engagement with the body 2 for moving it back and forth properly to adjust the chasers for diameter and at its forward end encircling the collar 13 in such manner that it provides a shoulder abutting the rear of the cam 16.

Surrounding the two collars l3 and I9- is an This tap is designed for attachment either to I a rotary spindle, in which case the tap rotates and the'work is held against rotation, or it may be attached to a non-rotatable spindle, in which case the workwill rotate while the tap is held against rotation.

When the tap is attached to a rotatable spindle, this hood 2! may be provided with a circumferential groove 24 for the reception, of the usual fork on the machine adapted to shift the hood back and forth at the proper time to open and close the chasers.

When the tap is attached to a stationary or non-rotatable spindle, this hood is shifted in one direction by means of a Work engaging member 25 connected to the hood by means of slotted arms or fingers 26 and returned or shifted in the other direction by means of an arm or lever 21 as is usual in taps of this nature and, therefore, a' detailed description thereof is not thought necessary herein. I Y

Projectinginwardly on the inside wall of the hood 2| is a circumferential projection 28 having its rear edge 29 beveled to correspond with the bevel of the cam i6 and the front edge forming an abutment shoulder for the projecting ends of the tie bar M. I

As before stated, this tie bar It is carried by the collar 13 and is adapted to extend through the elongated slots 3! of the body 2 and a somei what shorter elongated slot 32 of the core piece I.

The operation of the tap is as follows:

When the thread cutting operation has been When this cam is depressed below the shoulder of the adjusting sleeve I9, the spring 8 ordinarily pulls back the core piece I and collar 13 but, under heavy cutting action of the chasers or if the chasers hit a shoulder while threading, frequently they tend to set up a torque on the sides of the slots and also on the core piece 1 that would tend to prevent the core from receding freely and thus prevent collapse of the chasers.

Such a situation is overcome in the present construction because the hood, in moving back relative to the body before it fully depresses the cam l6, sets up a tension in the springs 23 because, at this time, the collar is held against axial movement. However, when the cam I6 is depressed below the shoulder 20 of the ring I 9, since there is no cutting strain on this part of the tap, the collar [3 will be moved freely by the springs 23 and this movement will carry the tie bar M in the slot 32 of the core until it contacts the core at the end of the slot, when it will give the core a kick action and insure proper withdrawal of the core under the operation of the spring 8.

Thus, itwill be seen that this invention provides a positive action in the collapse of the chasers due to the sudden kicking action of the tie bar on the core piece which will offset any torque set up and insure the proper withdrawal of the chasers from the work.

To reset the tap, either a fork on the machine acting in the groove 24, or the hand lever 27 may be used and since the shoulder30 of the projection 28 contacts the tie bar l4, forward movement of the hood will carry the tie bar l4, collar I3 and core piece 1 forward relative to the body until the trigger cam 16 passes the shoulder 20 of the adjusting ring I!) whereupon the springs l8 will force the cam. 16 outwardly tothe position shown in Fig. 1. When this trigger cam l6 has been forced outwardly, the

spring 8 willcause the core piece I, collar I3 and cam 16 all to be held back to the proper position and the chasers will be accordingly reset for the proper cutting position in conformity with the setting of the size adjusting ring I9.

It is to be understood that, by describing in detail herein any particular form, structure or arrangement, it is not intended to limit the invention beyond the terms of the several claims or the requirements of the prior art.

the thread cutting operation, means for releasing the trigger to permit movement of said sleeve upon completion of the thread cutting operation, and means for moving the sleeve and including a spring activated member extending transversely of the body.

2. A threadingtool having a body, chasers carried thereby, means for normally retracting the chasers at the end of the thread cutting operation, and supplemental means for insuring the retraction of the chasers, said supplemental means comprising a sleeve, a trigger for holding Having thus explained the nature of my. said i invention and described a way of constructing the same, although without attempting to set forth all of the forms inwhich it may be made, or all of the modes of its use, I claim:

1. A threading tool having a body, chasers carried thereby, means for normally retracting the chasers at the end of the thread cutting operation, and supplemental means for insuring the retraction of the chasers, said supplemental means comprising a sleeve, a trigger for holding it against movement relative to the body during it against movement relative to the body during the thread cutting operation, means for releasing the trigger topermit movement of said sleeve upon completion of the thread cutting operation,

and means for moving the sleeve, said last means comprising spring means and said sleeve shiftable relative to the normal retracting means and provided with means for kicking the normal retracting means into operation.

3. A threading tool having a body, chasers carried thereby, means for collapsing the chasers s at the end of the thread cutting operation, an

axially movable. sleeve carried by the body, means for holdingthe sleeve against movement during the thread cutting operation and operative to permit movement upon the completion thereof, means carried by the sleeve effective to insure operation of the collapsing means, means for initially moving the sleeve independently of the collapsing means, and means connecting the sleeve and collapsing means whereby upon failure of the collapsing means to operate the sleeve will be shifted to kick the collapsing means and initiate movement thereof, said connecting means comprising a spring actuated tie bar carried by the sleeve and collapsing means and having a limited movement relative to the collapsing means;

4. A threading tool having a body, chasers carried thereby, a core piece shiftable relative to the body and having engagement with the chasers for retracting them upon completion of the thread cutting operation, means for normally retracting the core piece, and supplemental means for insuring retraction of the chasers and including a spring,,actuated member extending transversely of and shiftable in the core piece,

5. A threading tool having a body, chasers carried thereby, a core piece shiftable relative to the body and having engagement with the chasers; for retracting them upon completion of the thread cutting operation, and supplemental means for insuring retraction of the chasers, said supplemental means comprising a sleeve, a trigger'for holding it against movement relative to the body during the thread cutting operation, and means for releasing the trigger to permit movement of said sleeve upon completion of the thread cutting operation and means for moving the sleeve, a tie bar carried by the sleeve and extending into and having a sliding connection with the core piece whereby upon failure of the core piece to shift, the sleeve will have a limited movement relative thereto to kick the core piece and initiate movement thereof, and means for moving said sleeve and thereby the tie bar to kick the core piece.

6. A threading tool having a body, chasers carried thereby, a corepiece shiftable relative to the body and having engagement with the chasers for retracting'them upon completion of the thread cutting operation, and supplemental m ans for insur ng retraction ofthe' chasers, said supplementalrhe ns oifiprisiirigiasleeve, a'trig' ger fonholdir'ilg st movement relativeto the"body during t hread"slitting operation, means" orreleasin the" "ggerto permit'movea nieriearsaiu 'sle'veupon pletion of the thread cutting operation, andrneafis for moving "the sleeve, a tie bar carried by the sleeve and exten'diii'g'int'o and having'a sliding connection with the core piece whereby upon failure of the core piece to shift, the sleeve will have a limited movement relative thereto to kick the core piece and initiate movement thereof.

7. A threading tool having a body, chasers carried thereby, a core piece shiftable relative to the body and having engagement with the chasers for retracting them upon completion of the thread cutting operation, and supplemental means for insuring retraction of the chasers,

spring actuated tie bar carried by the sleeve and 7 extending into and having a sliding connection with the core piece whereby upon failure of the core piece to shift, the sleeve will have a limited movement relative thereto to kick the core piece and initiate movement thereof.

A threading tool having a chaser carrying body, a core piece shiftable relative to the body and having engagement with the chasers for retracting them upon completion of the thread cutting operation, means for shifting the core piece, means for preventing movement of the core piece during the thread cutting operation and permitting such movement upon completion tracting them upon completion of the thread cutting operation, means for shifting the core piece means for preventing shifting thereof during the thread cutting operation and permitting such shifting upon completion thereof, and supplemental means for insuring shifting of the core piece and including a spring actuated member extending transversely of and shiftable in the core piece.

10. A threading tool having a chaser carrying body, a core piece shiftable relative to the body v and having engagement with the chasers for retracting them upon completion of the thread cutting operation, means for shifting the core piece, means for preventing shifting thereof during the thread cutting operation and permitting such shifting upon completion thereof, and supplemental means for insuring shifting of the core piece, said supplemental means comprising a shiftable sleeve held against movement relative to the body during the thread cutting operation and shiftable upon completion thereof, means for shifting it, and means for connecting the sleeve and core piece whereby upon failure of the core shiftingmeans the sleeve will be shifted to engage the core piece and kick the core and initiate movement thereof.

retracting them upon completion of the thread cutting operation, means. for shifting the core piecef mean 's for' preventing [shifting thereof during he thread cutting operation and permitting 39, skii tingii qn m n' a p plemental meansfor insuring shifting of'the core piece, said supplemental means comprising a shiftable sleeve held against movement relative to the body during the thread cutting operation and shiftable upon completion thereof, means for shifting it, and means for connecting the sleeve and core piece whereby upon failure of the core shifting means the sleeve will be shifted to kick the core and initiate movement thereof, said connecting means comprising a tie bar carried by the sleeve and engaging the core piece and having a limited movement relative to the core.

12. A threading tool having a body, chasers carried thereby and means for collapsing the chasers out of the work upon completion of the thread cutting operation, said means comprising a pair of members stationary relativeto the body during the thread cutting operation and shiftable relative thereto upon completion thereof, means normally operable to shift both of said members in unison, means carried by one of said members and having sliding connection with the other of said members, and means operable to shift one of said members independently of the other a predetermined distance to kick the normally operable means into action upon failure of said normally operable means to shift the members in unison.

13. A threading die having a body, chasers carried thereby, a core piece stationary relativeto the body during the thread cutting operation and shiftable relative thereto upon completion of the thread cutting operation for retracting the chasers, means for shifting the core piece, and supplemental means for insuring retraction of the chasers and comprising a sleeve, means carried by the sleeve and extending into and having a sliding connection with the core piece and means for shifting the sleeve a predetermined distance relative to the core piece upon failure of the core piece to shift to kick the core piece and start shifting thereof.

14. A threading tool having a body, chasers carried thereby, a pair of members shiftable relative to said body for collapsing the chasers upon completion of the threading operation, means for shifting each of said members, means for holding the members against shifting, means for releasing the holding means to permit such shifting, means carried by one of said members and extending into and having sliding engagement with the other member, the means for shifting one of said members normally operable to shift both of said members in unison, and the means for shifting the other of said members operable to shift said member independently a predetermined distance to kick said other member and initiate operation of said normally op-- erable means upon failure of said normally operable shifting means.

15. A threading tool having a body, chasers carried thereby, a core piece shiftable relative to the body and having engagement with the chasers for shifting them and including means for primarily retracting the chasers upon completion of the thread cutting operation and supplemental means for insuring retraction of the chasers and comprising a member having a sliding engagement with the core piece and means for shifting said member thereby to kiek the core piece at a of the thread cutting operation, and supple- 4 mental means for insuring retraction of the chasers and comprising a shiftable member cooperating with said primary means to impart a kick. thereto upon the ,failure of said primary means to act, and'spring means for shifting said member to effect such kick.

I WILLIAM J. HOGG. 

